New culture medium concepts for cell transplantation.

BACKGROUND: Before cell or tissue transplantation, cells or tissues have to be maintained for a certain period in vitro using culture medium and methods. Most culture media contain substances such as pH indicators and buffers. It is not known whether some of these substances are safe for subsequent application in the transplantation of cells or tissues into the human body. We investigated culture media and methods with respect to the safety of the components in future transplantation applications. METHODS: A modified culture medium--medical fluid-based culture medium (FCM)--was designed by using various fluids and injectable drugs that are already currently permitted for use in clinical medicine. Medium components necessary for optimal cell growth were obtained from approved drugs. FCM was manufactured with adjusted final concentrations of the medium components similar to those in commercial Dulbecco's modified Eagle's medium (DMEM). In particular, 1029.40 mg/L amino acids, approximately 88.85 mg/L vitamins, 13,525.77 mg/L inorganic salts, and 4500 mg/L D-glucose comprise the high-glucose FCM. Next, human fat synovium-derived mesenchymal stem cells and rat H9c2 (2-1) cells were cultured under 2 conditions: (1) DMEM-high glucose (HG), an original commercial medium, and (2) optimized FCM-HG. We assessed the morphologies and proliferation rates of these cells. RESULTS: We observed that FCM-HG was able to induce the growth of FS-MSC and commercially available H9c2 cell. The morphologies and proliferation patterns of these cells cultured under FCM-HG showed no differences compared with cells grown in DMEM-HG. CONCLUSION: Our data suggest that FCM, which we developed for the first time according to the concept of drug repositioning, was a useful culture medium, especially in cultured cells intended for human cell transplantation.

Pseudoislet of hybrid cellular spheroids from commercial cell lines.

Investigators conducting diabetes-related research have focused on islet transplantation as a radical therapy for type 1 diabetes mellitus. Pancreatic islet isolation, an essential process, is a very demanding work because of the proteolytic enzymes, species, treatment time, and individual difference. Replacement of primary isolated pancreatic islets must be carried out continuously for various in vitro tests, making primary isolated islets a useful tool for cell transplantation research. Hence, we sought to develop pseudoislets from commercial pancreas-derived cell lines. In this study, we used RIN-5F and RIN-m cells, which secrete insulin, somatostatin, or glucagon. To manufacture hybrid cellular spheroids, the cells were cultured under hanging drop plate and nonadhesive plate methods. We observed that hybrid cellular pseudoislets exhibited an oval shape, with sizes ranging from 590 to 1200 µm. Their morphology was similar to naïve islets. Cell line pseudoislets secreted and expressed insulin, glucagon, and somatostatin, as confirmed by reverse transcriptase polymerase chain reaction, enzyme-linked immunosorbent assay, and immunohistochemistry analyses. Thus, the current artificially manufactured biomimetic pseudoislets resembled pancreatic islets of the endocrine system, appearing as cellular aggregates that secreted insulin, glucagon, and somatostatin. Enhanced immunoisolation techniques may lead to the development of new islet sources for pancreatic transplantation through this pseudoislet strategy.

Fragmin/protamine microparticle carriers as a drug repositioning strategy for cell transplantation.

BACKGROUND: The importance of drug repositioning has been gaining attention in the last few years, allowing existing pharmaceutical products to be reevaluated for potential alternative therapeutic applications. The purpose of this study was to evaluate the effects of fragmin/protamine microparticles (F/P MPs) on cell aggregates under the concept of drug repositioning. METHODS: Mesenchymal stem cells (MSCs) and embryonic rat heart-derived cardiac H9C2 cells were mixed with D-PBS, basal medium, fragmin, protamine, and F/P MPs to manufacture aggregates intended for cell transplantation. To evaluate their adhesive properties as cell carriers, we injected combinations of MSC aggregates into cartilage tissue, observing their leakage from the implantation site. RESULTS: Our data demonstrated that MSCs and H9C2 cells mixed with F/P MPs rapidly produced large, viscous cellular aggregates. F/P MPs were bound to the surface of MSCs and H9C2 cells; thus, F/P MPs induced the formation of F/P MP-cell aggregates. Cell aggregates were prevented from leaking from the transplanted site. CONCLUSION: Aggregation induced by F/P MPs may improve the efficiency of cell therapy, a novel method for transplantation.

Premature labour induced by cortisol in the unrestrained pregnant rabbit.

The relationship between electrical activity (EMG) of the uterus, progesterone levels and gap junctions was studied in pregnant rabbits delivering either prematurely (cortisol-induced) or spontaneously at term. Electrodes were implanted in the myometrium and a catheter was inserted into the jugular vein for continuous infusion of saline or cortisol from gestational age 25 days. A tether and swivel system was used to connect the electrodes and catheter to the recording unit thus allowing protection of the wires and catheters while enabling the rabbit to move freely. The EMG was recorded continuously from day 25 of pregnancy until animals either delivered or were sacrificed at predetermined days of gestation. Both rabbit groups showed a similarity in patterns of EMG, progesterone levels and gap junction formation. We conclude that preterm labour induced by cortisol mimics normal term labour.

Morbidity in general practice in Barbados

From September 1977, 11 general practitioners took part in a survey of 12 months' duration in which they recorded morbidity at every doctor-patient encounter. 35,143 patients made 53,094 encounters and a total of 62,932 problems were identified. The most common reason for going to the doctor was for examination with no disease detected. Acute upper respiratory tract infections, hypertension and pregnancy were the 3 most common specific problems with which the doctors dealt. The results demonstrated some features of general practice such as the abundance of the common diseases, the need to be alert to the infrequent occurrence of wide range major disease, pre-symptomatic screening of the healthy "at risk" patient and the problems of the ill-defined conditions. Comparisons with other surveys show some similarities in general practice morbidity, but also important differences that can be related to prevailing local conditions (AU)